Write a program to calculate area of circle.

#include<iostream>
using namespace std;

int main()
{
 float r,area;
 cout<< "\nEnter radius of circle : ";

 cin>>r;
 area = 3.14*r*r;

 cout<<"Area of circle : "<<area;
 
 return 0;
}

OUTPUT:

Enter radius of circle : 7
Area of circle : 153.86